The present invention relates generally to methods and apparatus for manufacturing insulating glass units. More particularly, the present invention relates to methods and apparatus for assembling muntin bar lattices and spacer frames for use in insulating glass units.
Today, insulating glass units have achieved widespread use as building components. In order to produce insulating glass units inexpensively and in high volume, the use of mechanized and/or automated assembly methods is desirable. An insulating glass unit may include, for example, a pair of panes and a spacing frame interposed between the panes. The panes and the spacing frame together define the sealed space. In some applications, a gas is disposed in the sealed space of the insulating glass unit.
In many applications, the panes of the insulating glass unit are transparent. When this is the case, the insulating glass unit may form a portion of a window. Windows allow the occupants of buildings to view the world outside while allowing sunlight to enter the interior of the building. Sunlight is a natural antidepressant and helps the human body produce vitamin D thus, a certain amount of sunlight is essential to mental and physical well being.
When the panes of the glass unit are transparent, it is desirable to keep the inside surfaces of the panes free from visible defects and contamination. One example of a visual defect occurs when particles are present in the sealed space and settle on the inside surfaces of the panes. A second example of a visual defect occurs when materials disposed within the sealed space out gas resulting in visible discolorations on or in the panes. A third example of a visual defect occurs when the gas in the sealed space contains moisture which condenses on the inside surfaces of the panes.
The present invention relates generally to methods and apparatus for manufacturing insulating glass units. More particularly, the present invention relates to methods and apparatus for assembling muntin bar lattices and spacer frames for use in insulating glass units. One method of assembling a muntin bar lattice in accordance with the present invention comprises the steps of providing a muntin bar segment and a keeper dimensioned for piercing a wall of the muntin bar segment. This method may also advantageously include the step of piercing the wall of the muntin bar with the keeper.
Additionally, the keeper may be placed in a desired position in which a first portion of the keeper extends beyond a first side of the muntin bar segment and a second portion of the keeper extends beyond a second side of the muntin bar segment. Certain implementations of the present invention may include the step of locking the keeper in the desired position. In these implementations, a keeper including a lock may be provided. A method in accordance with the present invention may also include the step of inserting the second portion of the keeper into a cavity of a second muntin bar segment. Additionally, the first portion of the keeper may be inserted into a cavity of a third muntin bar segment.
A keeper for joining a muntin bar segment to a second muntin bar segment in accordance with an exemplary embodiment of the present invention comprises an elongate body having a proximal end and a distal end. The body may advantageously include a tip portion disposed at the proximal end thereof. In certain implementations, the tip portion is dimensioned for piercing a wall of the muntin bar segment to create an opening therein.
In certain useful implementations of the present invention, the body has an overall thickness that is less than an overall thickness of the muntin bar. In certain advantageous implantations, the body has an overall thickness that is less than about half the overall thickness of the muntin bar. In one aspect of the present invention, the tip portion of the body includes a first cutting edge. In another aspect of the present invention, the first cutting edge has a length that is substantially equal to a thickness of the body.
The tip portion of the body may also include a second cutting edge disposed at a first angle relative to a longitudinal axis of the body. In another aspect of the present invention, the tip portion of the body may include a third cutting edge disposed at a second angle relative to the longitudinal axis of the body. In some implementations, the second angle is substantially equal to the first angle.
In certain advantageous implementations, the body of the keeper is substantially symmetrical about a longitudinal axis thereof. The body of the keeper may also be substantially symmetrical about a lateral axis thereof. In another aspect of the present invention, the body of the keeper has an overall width dimensioned to be received in a cavity of the second muntin bar segment.
In certain implementations, the muntin bar segment comprises a material having a first modulus of elasticity and the keeper comprises a material having a second modulus of elasticity greater than the first modulus of elasticity. Also certain implementations, the muntin bar segment comprises a material having a first yield strength and the keeper comprises a material having a second yield strength greater than the first yield strength. Also in certain implementations, the muntin bar segment comprises a material having a first hardness and the keeper comprises a material having a second hardness greater than the first hardness. In certain implementations, the muntin bar segment comprises aluminum and the keeper comprises stainless steel.
A keeper in accordance with the present invention may advantageously include a lock for holding the keeper in a desired position relative to a muntin bar segment. In certain implementations, the lock includes a ramping surface that is dimension to elastically deform the wall of the muntin bar segment. The lock may also advantageously include a locking surface that is dimension to cooperate with the wall of the muntin bar segment to prevent retrograde motion of the keeper.
A spacer for the separation of panes in an insulating glass unit in accordance with one exemplary embodiment of the present invention may include a tubular member comprising a wall defining a lumen and a mounting flange comprising a first portion of the wall that is doubled back upon itself. The mounting flange may advantageously include a plurality of mounting holes. In one aspect of the present invention, the mounting holes are dimensioned to receive a plurality of prongs of a clip. The spacer may advantageously include a seam formed between a first leg of the mounting flange and a second leg of the mounting flange. In some implementations, the spacer also includes a second mounting flange comprising a second portion of the wall that is doubled back upon itself.
A spacer in accordance with the present invention may further include a plurality of granules disposed within a lumen of the spacer. The granules may advantageously comprise, for example, a desiccant (e.g., molecular sieve) and/or a filler material (e.g., clay).
A spacer for the separation of panes in an insulating glass unit in accordance with another exemplary embodiment of the present invention may comprise a tubular member defining a first lumen and a second lumen. A seal may be advantageously interposed between the first lumen and the second lumen. The spacer may advantageously include a plurality of mounting holes communicating with the second lumen and separated from the first lumen by the seal.